ML20156A299
| ML20156A299 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/04/2020 |
| From: | V Sreenivas NRC/NRR/DORL/LPL1 |
| To: | David Helker, Deborah Neff Exelon Nuclear |
| Sreenivas V, 415-2597 | |
| References | |
| EPID L-2020-LLA-0043 | |
| Download: ML20156A299 (2) | |
Text
From:
Sreenivas, V To:
Neff, David B:(Exelon Nuclear); Helker, David P:(Exelon Nuclear)
Cc:
Danna, James; Bedi, Gurjendra; Buford, Angela; Huang, Jason; Greives, Jonathan; Patel, Jigar
Subject:
LIMERICK GENERATING STATION, UNITS 1 AND 2: RAI FOR RR TO USE INSERVICE TESTING PROGRAM SAFETY RELIEF VALVE TESTING EPID No. L-2020-LLA-0043 Date:
Thursday, June 4, 2020 10:53:00 AM In a submittal dated February 5, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20036E488), Exelon Generation Company, LLC (licensee) requests authorization by the U.S. Nuclear Regulatory Commission (NRC) of a proposed alternative associated with the lnservice Testing (IST) Program for the Limerick Generating Station, Units 1 and 2 in accordance with 10 CFR 50.55a(z)(1). In its request, the licensee proposes to extend the IST Program testing frequency for certain Safety Relief Valves (SRVs) to eight years. Upon review, the NRC staff requests the licensee that the additional information is needed to complete its review related to the application under the EPID No. L-2020-LLA-0043.Further to technical clarification call held on June 2, 2020, the RAI EMIB-1 is revised as follows, considering the Exelon fleet action.
RAI EMIB-1 (Revised)
Currently, each of the Exelon facilities in the below table1 is required to test at least 20 percent of the SRVs every 24 months. As an alternative to this requirement, the licensee proposes to test 40 percent of the SRVs at each facility within a 48-month interval. For each facility, the SRV models affected by the proposed alternative are listed in the table below.
Under the proposed alternative, it is possible for more than 24 months to elapse between tests of an SRV model.
Facility SRV Models Clinton Dikkers Model G-471 Dresden Units 2 and 3 Target Rock 3-Stage Model 67F Nine Mile Point Unit 2 Dikkers Model G-471 Peach Bottom Units 2 and 3 Target Rock Models73-67F and 74-67F Quad Cities Units 1 and 2 Target Rock 3-Stage Model 74-67F and Dresser Model 3777Q Limerick Units 1 and 2 Target Rock Model 98-67F
Describe any plans to coordinate and share data regarding the SRV testing program at different units and sites that have the same SRV Target Rock model as Limerick Units 1 and 2. Describe any measures to obtain information on the performance of the Target Rock model SRVs at intervals more frequent than once every 48 months, such as staggering the testing at different reactor units that have the same SRV model.
1 Reference Exelon Generation Company, LLC - Request for Additional Information Regarding Request to Extend Safety Relief Valve Test Interval, dated May 14, 2020 (ADAMS Accession No. ML20135H197)
RAI EMIB-2 During a public meeting on June 4, 2019, Exelon provided a presentation to the NRC staff to discuss the proposal to extend the SRV test interval at Exelon boiling water reactor (BWR) nuclear power plants to 8 years with 40% of the group tested every 48 months,
instead of 20% every 24 months with a shorter test interval. See ADAMS Accession No. ML19151A660. The Exelon presentation specified four pillars of Exelon SRV/MSSVs Best Practices: (1) Spring Testing - includes physical dimension measurements and compression rate evaluation; (2) SRV/MSSVs Lapping Techniques and Tools; (3)
SRV/MSSVs Set Pressure Adjustment Methodology Precision; and (4) Target Rock SRV/MSSVs Average Delay Time Trending Performance Improvement. The licensees submitted alternative request for Limerick Units 1 and 2 refers to the Exelon SRV Best Practices described during the public meeting on June 4, 2019. For implementing the proposed alternative request at Limerick Units 1 and 2, please describe the planned implementation of the Exelon SRV/MSSVs Best Practices, including the four pillars of Exelon SRV/MSSVs Best Practices.
Please submit the response no later than June 29, 2020. If you have any questions, please contact me.
V. Sreenivas, Ph.D., CPM.,
Licensing Project Manager (Operating Reactors)
Limerick and Ginna Nuclear Power Plants USNRC/NRR/DORL/LPL1 (301) 415-2597; vxs1@nrc.gov